Polydactyl Cats: An Amazing Genetic Mutation

Have you ever encountered a cat whose paws look like “mittens”? If not, you are missing an enchanting experience.

These cats sporting numerous toes are one of the most awesome and fascinating felines; albeit their appearance can be somewhat bizarre to folks who have never seen one. In the United States, these supernumerary-toed kitties have often been called “mitten cats” or “Hemingway” cats.

Ernest Hemmingway (the best-selling author of “The Old Man and the Sea” and countless other famous popular classic novels) was a passionate cat lover. He was presented with Snowball (a polydactyl cat) as a personal gift by a ship’s captain in 1933. Snowball went on to produce many litters of ploydactyl kittens (the gene passes on). As many as 50 of Snowball’s ancestors are living the life of luxury today; spoiled and pampered by the staff at the Hemingway Home Museum in Key West, Florida.

Polydactyl cats have more than the usual number of toes on one or more of their paws. These kitties are born with an abnormal, dominant genetic mutation called polydactylism. While the polydactyl cat’s appearance is quite unique, the polydactyl gene is somewhat common.

Normally kittens are born with five toes on their front paws and four in the back. But for the female cat to produce at least one kitten with extra toes, one of the parents must carry the gene that is responsible for polydactylism. However, if both parents carry the gene, this increases the probability that all of their kittens will be polydactyl.

Interestingly enough, the number of extra toes polydactyl kittens are born with may also vary and they may not have the identical number of toes of their parents. It is also much more common for extra toes to appear on the front paws than it is to have developed on the hind paws. Kittens who are born with extra toes on all four paws are extremely rare.

Many feline lovers think polydactyls are alluring and quite mysterious. But what is it about these remarkable kitties that makes them so different from cats who have a normal number of digits on their paws? Additionally, what causes polydactylism, making them so different from ordinary kitties?

Arnold Plotnick, DVM, a noted feline-only veterinarian (now retired), has a very special place in his heart for these kitties because he is owned by one. According to Dr. Plotnick, many polydactyl cats have one or two extra toes on both paws appearing on the thumb side of the foot.

Dr. Plotnick writes, “Polydactylism is a common trait among cats. But polydactylism doesn’t affect cats adversely. It offers them no advantages, nor does it yield any disadvantages. If it had disadvantages, polydactyl cats most likely would have died out. It is simply an enchanting quirk.”

According to Dr. Plotnick, polydactylism rarely has any negative effects on these cats. The toenails on their extra toes are generally normal nails. Occasionally the extra toe may be incompletely formed and the nail bed deformed which may lead to a claw issue that is similar to an ingrown/overgrown claw. These cats rarely get caught on carpets or furnishings, and just like normal claws the extra claws require regular trimming.

It is possible that the origin of the polydactyl cat may be linked to the unregistered Maine Coon cats that had an incidence of polydactylism close to 40 percent. Although the polydactyl cat is not a separate breed, their origin may be linked to polydactyl Maine Coon cats. Polydactylism occurring in any registered feline breed is considered an undesirable trait – they are not accepted in cat shows for championship competition.

Hemingway cats, mitten cats, or whatever they are called, are simply stunning creatures that are greatly cherished by their owners. Want to see one up close and purrsonal? Take a trip down to the Florida Keys and visit the Hemingway Museum. It is rumored that the Hemingway clowder is quite affectionate and greatly enjoy tourist attention.